IP routing is the process of using IP addresses to forward IP packets from their source to a new destination. Routing usually involves packet switching, and in the case of IP routing, the IP adopts packet switching.
When a person sends information from one computer to another through the Internet, IP routing occurs. For instance, if a person were to send a message to a friend's machine in a different country, the information would first be sent to an IP protocol module, where data packets are bundled into IP packets, and then sent over the Internet.
The data packets will then cross through several routers to reach the destination of the new computer. The work that the routers do to move the data packet forward is known as routing. Every data packet that is moved through the Internet holds two IP addresses, which are the IP address of the machine where the original message came from and the IP address of the destination.
A data packet can take different paths and move through different networks, but they all eventually get routed into the same destination. When the data packet reaches its destination, the IP address and the machine address will match, which allows the IP module to reassemble the data and send it to the TCP service to be processed.